Ankle brachial pressure index (ABPI): An update for practitioners

The reliability of the ankle brachial index: a systematic review

BACKGROUND

The ankle brachial index (ABI) is widely used in clinical practice as a non-invasive method to detect the presence and severity of peripheral arterial disease (PAD). Current guidelines suggest that it should be used to monitor potential progression of PAD in affected individuals. As such, it is important that the test is reliable when used for repeated measurements, by the same or different health practitioners. This systematic review aims to examine the literature to evaluate the inter- and intra-rater reliability of the ABI.

METHODS

A systematic search of MEDLINE, EMBASE and CINAHL Complete was conducted to 20 January 2019. Two authors independently reviewed and selected relevant studies and extracted the data. Methodological quality was determined using the Quality Appraisal of Reliability (QAREL) Checklist.

RESULTS

Fifteen studies of ABI reliability in a range of patient populations were identified as suitable for inclusion in the review: seven considered inter-rater reliability, four intra-rater reliability, and four studies evaluated both inter- and intra-rater reliability. Inter-rater reliability was found to be highly variable, with intraclass correlation coefficients (ICC's) ranging from poor to excellent (ICC 0.42-1.00), while intra-rater also demonstrated considerable variation, with ICCs from 0.42-0.98. Meta-analysis was not possible due to the lack of statistical information reported.

CONCLUSIONS

Results of included studies suggest the inter- and intra-tester reliability of the ABI is acceptable. However, inconsistencies in obtaining systolic pressure measurements, calculating ABI values, and incomplete reporting of methodologies and statistical analysis make it difficult to determine the validity of the results of included studies. Further research, with more consistent reliability methodology, statistical analysis and reporting conducted in populations at risk of PAD is needed to conclusively determine the ABI reliability.

Global Vascular Guidelines on the Management of Chronic Limb-Threatening Ischemia

GUIDELINE SUMMARY

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

Global vascular guidelines on the management of chronic limb-threatening ischemia

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

Ankle Brachial Pressure Index: An update for the vascular specialist and general practitioner

Objectives

Ankle brachial pressure index (ABPI) is an invaluable tool for assessing the severity of peripheral arterial disease. In addition, it can be used as an independent marker of cardiovascular risk, with a predictive ability similar to the Framingham criteria. Identification of an abnormal ABPI should therefore trigger aggressive cardiac risk factor modulation for a patient. Unfortunately, the significance of abnormal ABPIs is poorly understood within the general medical community. This is compounded by the influence of various comorbidities on accurate measurement of ABPI, potentially leading to a wide variability in readings that need to be considered before interpretation in these patient populations. We aim to address these issues by revealing several common misunderstandings and pitfalls in ABPI measurement, describing accurate methodology, and highlighting patient cohorts in whom additional or alternative approaches may be required.

Methods

We present a narrative review of the role of ABPI in both the community and hospital setting. We have performed a literature review, exploring the validity and reproducibility of methodology for obtaining ABPI, alongside the utility of ABPI in different clinical scenarios.

Results

The measurement of ABPI is often performed incorrectly. Common pitfalls include inadequate patient preparation, failure to obtain the blood pressure from the correct lower limb artery in patients with tibial disease, failure to account for differences in brachial blood pressure between the arms, inappropriately chosen equipment and patient factors such as highly calcified arteries. Standardisation of methodology greatly improves reliability of the test. Exercise ABPI can identify significant peripheral arterial disease in patients with normal resting ABPI. In addition to its role in peripheral arterial disease, ABPI measurement has a role in assessing venous ulcers, entrapment syndromes and injured extremities; conversely, it has a more limited utility in the diabetic population.

Conclusions

A thorough understanding of the correct technique and associated limitations of ABPI measurement is essential in accurately generating and interpreting the data it provides. With this knowledge, the ABPI is an invaluable tool to help manage patients with peripheral arterial disease. Perhaps more importantly, ABPI can be used to identify and risk stratify patients with asymptomatic peripheral arterial disease, itself a major indicator of significant underlying cardiovascular disease. With the emergence of best medical therapy, targeted pharmacotherapy and lifestyle changes can reduce the risk of major cardiovascular events in high-risk patients by approximately 30%, particularly in diabetic patients. Therefore, the utility of ABPI transgresses vascular surgery, with an essential role in general practice and public health.

Lower sensitivity of ankle-brachial index measurements among people suffering with diabetes-associated vascular disorders: A systematic review

Diabetes mellitus is a systemic disease affecting microvascular and macrovascular systems and is considered as the strongest risk factor for peripheral arterial disease. Although the prevalence of the peripheral arterial disease is high among people living with diabetes, its severity is not accurately detected with the prevalent diagnostic methodologies. The ankle-brachial index measurement is a simple, objective, and reliable tool for diagnosis of peripheral arterial disease. However, it is of limited value in the diagnosis of peripheral arterial disease among diabetic patients due to its low sensitivity among diabetic individuals. Diabetes mellitus results in atherosclerosis and calcification of peripheral arterial walls leading to false normal ankle-brachial index values. Therefore, healthcare practitioners should be careful not to misinterpret ankle-brachial index results among diabetic patients. A literature search was conducted using the keywords “ankle-brachial index,” “interpretation,” “limitations,” “diabetic foot,” and “peripheral arterial disease” on different medical search engines. The results were manually scanned and then further reviewed to select the articles related to our topic of discussion. This article will review the use of ankle-brachial index measurement among diabetic patients, its limitations and its prognostic value. In Conclusion, Ankle-brachial index can be used for diagnosis of peripheral arterial disease with some precautions (e.g. raising the threshold of diagnosis or using the lowest systolic pressure value measured at the ankle) and can also be a prognostic indicator for cardiovascular morbidity and mortality.

Clinical Assessment of Peripheral Arterial Disease in the Office: What Do the Guidelines Say?

Lower extremity peripheral arterial disease (PAD) is the manifestation of atherosclerotic disease within the lower extremities. The presentation of PAD is diverse ranging from asymptomatic disease to claudication or to debilitating rest pain, nonhealing ulcers, and gangrene. PAD is associated with significant morbidity, mortality, and healthcare costs. Proper diagnosis and management of PAD is important so as to maintain quality of life and reduce the risk of cardiovascular disease and adverse limb events such as amputation. This document provides a comprehensive outpatient approach to the clinical assessment of PAD that includes risk factors, diagnosis, treatment, and follow-up options.

Resilience to cognitive impairment in the oldest-old: design of the EMIF-AD 90+ study

BACKGROUND

The oldest-old (subjects aged 90 years and older) population represents the fastest growing segment of society and shows a high dementia prevalence rate of up to 40%. Only a few studies have investigated protective factors for cognitive impairment in the oldest-old. The EMIF-AD 90+ Study aims to identify factors associated with resilience to cognitive impairment in the oldest-old. In this paper we reviewed previous studies on cognitive resilience in the oldest-old and described the design of the EMIF-AD 90+ Study.

METHODS

The EMIF-AD 90+ Study aimed to enroll 80 cognitively normal subjects and 40 subjects with cognitive impairment aged 90 years or older. Cognitive impairment was operationalized as amnestic mild cognitive impairment (aMCI), or possible or probable Alzheimer's Disease (AD). The study was part of the European Medical Information Framework for AD (EMIF-AD) and was conducted at the Amsterdam University Medical Centers (UMC) and at the University of Manchester. We will test whether cognitive resilience is associated with cognitive reserve, vascular comorbidities, mood, sleep, sensory system capacity, physical performance and capacity, genetic risk factors, hallmarks of ageing, and markers of neurodegeneration. Markers of neurodegeneration included an amyloid positron emission tomography, amyloid β and tau in cerebrospinal fluid/blood and neurophysiological measures.

DISCUSSION

The EMIF-AD 90+ Study will extend our knowledge on resilience to cognitive impairment in the oldest-old by extensive phenotyping of the subjects and the measurement of a wide range of potential protective factors, hallmarks of aging and markers of neurodegeneration.

TRIAL REGISTRATION

Nederlands Trial Register NTR5867 . Registered 20 May 2016.

Pulse Oximetry as a Screening Test for Hemodynamically Significant Lower Extremity Peripheral Artery Disease in Adults with Type 2 Diabetes Mellitus

Objective

The main objective is to determine if digital pulse oximetry is an acceptable screening tool to detect hemodynamically significant lower extremity peripheral artery disease (PAD) in patients 50 years old and above with type 2 diabetes mellitus (T2DM) seen at the University of Santo Tomas Hospital (USTH).

Methodology

A total of 78 subjects (155 limbs) were included. Using duplex ultrasonography as the reference standard for the presence of hemodynamically significant lower extremity PAD, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were obtained for abnormal percent oxygen saturation (SpO₂) gradients and for ankle-brachial index (ABI).

Results

Of the 155 limbs, 38.7% had hemodynamically significant stenosis. Pulse oximetry had 76.7% sensitivity (95% CI, 65.2% to 88.1%), 85.3% specificity (95% CI, 78.0% to 92.6%), 76.7% PPV (95% CI, 66.5% to 84.4%) and 85.3% NPV (95% CI, 78.4% to 90.2%). ABI had 40.7% sensitivity (95% CI, 30.1% to 51.3%), 88.2% specificity (95% CI, 80.0% to 96.3%), 68.6% PPV (95% CI, 53.6% to 80.4%) and 70.1% NPV (95% CI, 65.1% to 74.5%). Combining both produces 88.1% sensitivity (95% CI, 78.5% to 97.8%), 74.2% specificity (95% CI, 65-83.4%), 68.4 PPV (95% CI, 60.3% to 75.6%) and 90.8% NPV (95% CI, 83.0% to 95.2%).

Conclusion

The results of this study suggest that pulse oximetry has a higher sensitivity than ABI as a screening tool for hemodynamically significant lower extremity PAD in T2DM patients 50 years old and above. Combining these two tests may be done to achieve a higher sensitivity.

Acupuncture Combined with Hydrotherapy in Diabetes Patients with Mild Lower-Extremity Arterial Disease: A Prospective, Randomized, Nonblinded Clinical Study

Background

The aim of this pragmatic study was to explore the intervention of acupuncture combined with hydrotherapy and perceived effects in type 2 diabetic patients with recently diagnosed, mild, lower-extremity arterial disease (LEAD) in comparison with a control group.

Material/Methods

One hundred twenty-six diabetes patients who were diagnosed mild LEAD according to ankle-brachial blood pressure index (ABPI) and peripheral neuropathy symptom were randomly assigned to either an experimental (n=64) or control group (n=62). The experimental group attended and completed (1) a 30-min session of acupuncture in certain selected points, and (2) a 30-min hydrotherapy exercise every 2 days for 15 weeks. The outcome parameters were assessed at baseline, after intervention, and at 6-week follow-up.

Results

The intervention was associated with an improvement in leg flow conductance and partial physical capacities, including chair-sit-and-reach, the walking impairment questionnaire (WIQ), and physical component summary score (PCS), compared to the control group. The treatment benefits were sustained throughout the 6-week follow-up endpoint. There was no difference in fasting glucose levels, Hb1Ac, blood pressure, or BMI after the intervention. At the endpoint of 6-week follow-up, acupuncture plus hydrotherapy appeared to reduce inflammatory response by decreasing IL-6, TNF-α, malondialdehyde, and SOD, and increasing glutathione.

Conclusions

Acupuncture plus hydrotherapy, without significant glycemic-controlling effects in the type 2 diabetic patients with mild LEAD, exerts a measurable benefit in disease-specific physical functions and health-related quality of life. Our results suggest that the combined therapy regulates the inflammatory process and oxidative stress and contributes to immune protection.

Extracorporeal shockwave therapy for intermittent claudication: Medium-term outcomes from a double-blind randomised placebo-controlled pilot trial

Objectives Peripheral arterial disease most commonly presents as intermittent claudication (IC). Early evidence has suggested that extracorporeal shockwave therapy is efficacious in the short term for the management of intermittent claudication. The objective of this pilot trial was to evaluate the medium-term efficacy of this treatment. Methods This double-blind randomised placebo-controlled pilot trial randomised patients with unilateral intermittent claudication in a 1:1 fashion to receive extracorporeal shockwave therapy or a sham treatment for three sessions per week over three weeks. Primary outcomes were maximum walking distance and intermittent claudication distance using a fixed-load treadmill test. Secondary outcomes included pre- and post-exertional ankle-brachial pressure indices, safety and quality of life assessed using generic (SF36, EQ-5D-3L) and disease-specific (vascular quality of life) measures. All outcome measures were assessed at 12 months post-treatment. Results Thirty participants were included in the study (extracorporeal shockwave therapy, n = 15; sham, n = 15), with 26 followed up and analysed at 12 months (extracorporeal shockwave therapy, n = 13; sham, n = 13). Intragroup analysis demonstrated significant improvements in maximum walking distance, intermittent claudication distance and post-exertional ankle-brachial pressure indices ( p < 0.05) in the active treatment group, with no improvements in pre-exertional ankle-brachial pressure indices. Significant improvements in quality of life were observed in 3 out of 19 domains assessed in the active group. A re-intervention rate of 26.7% was seen in both groups. Conclusions These findings suggest that extracorporeal shockwave therapy is effective in improving walking distances at 12 months. Although this study provides important pilot data, a larger study is needed to corroborate these findings and to investigate the actions of this treatment.

ISRCTN

NCT02652078.

Subclinical atherosclerosis, cardiovascular health, and disease risk: is there a case for the Cardiovascular Health Index in the primary prevention population?

Background

Current primary prevention guidelines for cardiovascular disease (CVD) prioritize risk identification, risk stratification using clinical and risk scores, and risk reduction with lifestyle interventions and pharmacotherapy. Subclinical atherosclerosis is an early indicator of atherosclerotic burden and its timely recognition can slow or prevent progression to CVD. Thus, individuals with subclinical atherosclerosis are a priority for primary prevention. This study takes a practical approach to answering a challenge commonly faced by primary care practitioners: in patients with no known CVD, how can individuals likely to have subclinical atherosclerosis be easily identified using existing clinical data and/or information provided by the patient?

Methods

Using NHANES (1999–2004), 6091 men and women aged ≥40 years without any CVD comprised the primary prevention population for this study. Subclinical atherosclerosis was determined via ankle-brachial index (ABI) using established cutoffs (subclinical atherosclerosis defined as ABI (0.91–0.99); normal defined as ABI (1.00–1.30)). Three common scores were calculated: the Framingham Risk Score (FRS), the Metabolic Syndrome (MetS), and the Cardiovascular Health Index (CVHI). Logistic regression analysis assessed the association between these scores and subclinical atherosclerosis. The sensitively and specificity of these scores in identifying subclinical atherosclerosis was determined.

Results

In eligible participants, 3.8% had subclinical atherosclerosis. Optimum and average CVHI was associated with decreased odds for subclinical atherosclerosis. High, but not intermediate-risk, FRS was associated with increased odds for subclinical atherosclerosis. MetS was not associated with subclinical atherosclerosis. Of the 3 scores, CVHI was the most sensitive in identifying subclinical atherosclerosis and had the lowest number of missed cases. The FRS was the most specific but least sensitive of the 3 scores, and had almost 10-fold more missed cases vs. the CVHI. The MetS had “middle” sensitivity and specificity, and 10-fold more missed cases vs. the CVHI.

Conclusions

Results from this study suggest that routine administration of the CVHI in a primary prevention population would yield the benefits of identifying patients with existing subclinical CVD not identified through traditional CVD risk factors or scores, and bring physical activity and nutrition to the forefront of provider-patient discussions about lifestyle factors critical to maintaining and prolonging cardiovascular health.

The importance of accurate methodology in ABPI calculation when assessing lower limb wounds

Recent health economic publications have highlighted the cost of wound care and demonstrated the important role played by community and practice nurses in delivering care. Leg ulcers form a significant proportion of the wounds managed in the community. Data indicates that many patients are managed with no specific diagnosis or without calculation of the ankle brachial pressure index (ABPI), despite care guidelines emphasising the importance of a full assessment including Doppler ABPI calculation in patient management. This article highlights the important role Doppler ABPI plays in patient assessment and describes the methodology, focusing on the importance of correct application of the technique if reliable reproducible results are to be obtained. The rationale for obtaining blood pressure readings from both arms is discussed, and the possible error resulting from reliance on single upper limb blood pressure measurement for both manual and automated ABPI calculation is highlighted and its impact on ABPI calculation illustrated.

The inter-rater reliability between nurse-assessors clinically assessing infection of chronic wounds using the WUWHS criteria

The aim of this study was to determine the inter-rater reliability between one expert-nurse and four clinical-nurses who were asked to clinically assess infection of chronic wounds by using the World Union of Wound Healing Societies (WUWHS) criteria. A quasi-experimental design was used to collect the data. In comparison to phase 1 in which 'open questions' were asked, in phase 2 a pre-printed form (checklist) was introduced. In both phases, 55 chronic wounds were clinically assessed. For each WUWHS criterion the inter-rater reliability of signs and symptoms was expressed by Cohens Kappa (κ). A substantial agreement (κ ≥ 0·6) was considered as adequate. In both phases pocketing (p < 0·02), and erythema (p < 0·004) scored statistically significant results. Phase 2 showed higher inter-rater agreements compared with phase 1 (three substantial agreements (easily bleeding/friable granulation tissue, delayed healing, increasing exudate), an almost perfect- and a perfect agreement for malodour and pain, respectively. According to the results it can be concluded that the clinical assessment of infection of chronic wounds may be better supported by a pre-printed form than making use of an 'open questions' form. To provide this with a higher level of evidence, there is need for more well conducted studies.

The importance of community screening of asymptomatic elderly for peripheral arterial disease by Doppler ultrasound and ankle-brachial index

Background

Peripheral arterial disease is an atherosclerotic disease characterized by an increase in morbidity and mortality. For these reasons early diagnosis of peripheral arterial disease is important. Ankle-brachial systolic pressure index measurement is frequently used in screening studies. Evaluating waveforms of distal lower extremities with Doppler ultrasound can be used as a screening program and provides more accurate information on peripheral arterial disease.

Aim

We investigate the prevalence of peripheral arterial disease, compare the efficacy of Doppler ultrasound evaluation of distal lower extremity waveforms and ankle-brachial systolic pressure index measurement in screening programs, and discuss the importance of early diagnosis of asymptomatic cases.

Material and methods

A total of 457 patients over the age of 65 (between 65 and 94, mean age: 71.4) including 270 males and 187 females were examined with Doppler ultrasound, had ankle-brachial systolic pressure index measurement taken and were screened for peripheral arterial disease. The correlation between Doppler ultrasound findings and ankle-brachial systolic pressure index was examined.

Results

According to the Doppler ultrasound findings, in the aortoiliac (r = 0.648) and femoropopliteal (r = 0.564) area, there is a medium level of correlation between severe stenosis and occlusions and a low ankle-brachial systolic pressure index value, and a low level of correlation between such abnormalities in the tibioperoneal region (r = 0.116) and a low ankle-brachial systolic pressure index value. Therefore, while the sensitivity of ankle-brachial systolic pressure index increases in proximal stenosis, it decreases in distal stenosis.

Conclusion

Despite the fact that ankle-brachial systolic pressure index is a diagnostic test commonly used in screening studies, evaluation of distal arteries by means of Doppler ultrasound provides more accurate information in terms of the identification of peripheral arterial disease.

Subjecting the ankle-brachial index to timely scrutiny: is it time to say goodbye to the ABI?

Although the ankle-brachial index (ABI) has been used as an indicator of peripheral artery disease and vascular supply to the foot for over 50 years, it is now associated with reservations and qualifying empirical evidence to the extent that the provocative step of abandoning it totally might be advisable. In this article, the results of three publications concerning the ABI are initially described in some depth and the results from eight additional publications are then summarized more briefly. Cumulatively, the research indicates that ABIs that seem to be normal, as well as those in the subnormal range, are often inflated by medial arterial calcification and can therefore produce a high proportion of false-negative screening test results for arterial disease as well as a misleadingly high impression of vascular sufficiency to the lower extremity. The toe-brachial index is suggested as being likely to overcome the problems associated with the ABI, and other alternatives to the ABI and TBI are acknowledged.

Alterations in cardiovascular system under artificially simulated microgravity: preliminary study

The main goal of this work is to study the alterations occurred in human cardiovascular system under artificially simulated microgravity by using special short-arm centrifuge. We have used arterial blood pressure, ankle-brachial pressure index and accelerated photoplethysmography approach to determine the effects of artificially simulated microgravity on vascular system. The group of 30 healthy male volunteers was studied in a short-arm human centrifuge at two levels of gravity gradients along head-to-foot direction (Gz): normal gravity gradient of 1 Gz and so called microgravity mode of 0.7 Gz during 10 minutes at supine position lying at the nacelle.

Quantitative Evaluation of Rehabilitation Effect on Peripheral Circulation of Diabetic Foot

Diabetes may cause different foot problems, which could easily lead to infection, ulcers, and increasing risk of amputation due to nerve or vascular injury. In order to reduce the risk of amputation, Buerger's exercise is frequently used for rehabilitation to improve the blood circulation in lower limbs. However, it is difficult to evaluate the rehabilitation efficiency with Buerger's exercise objectively. In this study, a novel non-invasively optical system is developed to non-invasively monitor the change of the foot blood circulation before and after long-term Buerger's exercise. Radial basis function neural network is also used for classifying the healthy and diabetic groups from the change of relative total hemoglobin (HbT) concentration and tissue oxygen saturation (StO2) and providing an index to evaluate the rehabilitation efficiency with Buerger's exercise. Finally, the experimental results show that the relative HbT concentration and StO2 in lower limbs corresponding to different groups are significantly different and could be used as the factors for the classification of healthy subjects and diabetic foot patients. Moreover, the tendency of the relative HbT concentration and StO2 rise after the long-term rehabilitation with Buerger's exercise.

Galectin-3 in Peripheral Artery Disease. Relationships with Markers of Oxidative Stress and Inflammation

Galectin-3 is a modulator of oxidative stress, inflammation, and fibrogenesis involved in the pathogenesis of vascular diseases. The present study sought to characterize, in patients with peripheral artery disease (PAD), the localization of galectin-3 in arterial tissue, and to analyze the relationships between the circulating levels of galectin-3 and oxidative stress and inflammation. It also sought to compare the diagnostic accuracy of galectin-3 with that of other biochemical markers of this disease. We analyzed femoral or popliteal arteries from 50 PAD patients, and four control arteries. Plasma from 86 patients was compared with that from 72 control subjects. We observed differences in the expression of galectin-3 in normal arteries, and arteries from patients with PAD, with a displacement of the expression from the adventitia to the media, and the intima. In addition, plasma galectin-3 concentration was increased in PAD patients, and correlated with serologic markers of oxidative stress (F2-isoprostanes), and inflammation [chemokine (C−C motif) ligand 2, C-reactive protein, β-2-microglobulin]. We conclude that the determination of galectin-3 has good diagnostic accuracy in the assessment of PAD and compares well with other analytical parameters currently in use.

Surrogate and clinical endpoints for studies in peripheral artery occlusive disease: Are statistics the brakes?

BACKGROUND

The aim of this review is to present the available clinical and surrogate endpoints that may be used in future studies performed in patients with peripheral artery occlusive disease (PAOD). Importantly, we describe statistical limitations of the most commonly used endpoints and offer some guidance with respect to study design for a given sample size. The proposed endpoints may be used in studies using surgical or interventional revascularization and/or drug treatments.

METHODS

Considering recently published study endpoints and designs, the usefulness of these endpoints for reimbursement is evaluated. Based on these potential study endpoints and patient sample size estimates with different non-inferiority or tests for difference hypotheses, a rating relative to their corresponding reimbursement values is attempted.

RESULTS

As regards the benefit for the patients and for the payers, walking distance and the ankle brachial index (ABI) are the most feasible endpoints in a relatively small study samples given that other non-vascular impact factors can be controlled. Angiographic endpoints such as minimal lumen diameter (MLD) do not seem useful from a reimbursement standpoint despite their intuitiveness. Other surrogate endpoints, such as transcutaneous oxygen tension measurements, have yet to be established as useful endpoints in reasonably sized studies with patients with critical limb ischemia (CLI).

CONCLUSIONS

From a reimbursement standpoint, WD and ABI are effective endpoints for a moderate study sample size given that non-vascular confounding factors can be controlled.

Ankle-brachial index and incident diabetes mellitus: the atherosclerosis risk in communities (ARIC) study

Background

Individuals with peripheral artery disease (PAD) often have reduced physical activity, which may increase the future risk of diabetes mellitus. Although diabetes is a risk factor for PAD, whether low ankle-brachial index (ABI) predates diabetes has not been studied.

Methods

We examined the association of ABI with incident diabetes using Cox proportional hazards models in the ARIC Study. ABI was measured in 12,247 black and white participants without prevalent diabetes at baseline (1987–1989). Incident diabetes cases were identified by blood glucose levels at three subsequent visits (1990–92, 1993–95, and 1996–98) or self-reported physician diagnosis or medication use at those visits or during annual phone interview afterward through 2011.

Results

A total of 3305 participants developed diabetes during a median of 21 years of follow-up. Participants with low (≤0.90) and borderline low (0.91–1.00) ABI had 30–40% higher risk of future diabetes as compared to those with ABI of 1.10–1.20 in the demographically adjusted model. The associations were attenuated after further adjustment for other potential confounders but remained significant for ABI 0.91–1.00 (HR = 1.17, 95% CI 1.04–1.31) and marginally significant for ABI ≤ 0.90 (HR = 1.19, 0.99–1.43). Although the association was largely consistent across subgroups, a stronger association was seen in participants without hypertension, those with normal fasting glucose, and those with a history of stroke compared to their counterparts.

Conclusions

Low ABI was modestly but independently associated with increased risk of incident diabetes in the general population. Clinical attention should be paid to the glucose trajectory among people with low ABI but without diabetes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0476-4) contains supplementary material, which is available to authorized users.

Ankle to brachial systolic pressure index at rest increases with age in asymptomatic physically active participants

BACKGROUND

It is commonly acknowledged that the ability to use the ankle-brachial index (ABI), a reliable way to diagnose atherosclerosis, decreases with age in the general population. The aim of this study was to determine the relationship between resting ABI and age in different populations.

METHODS

674 physically active participants with (active high risk, ACT_HR) or without (active low risk, ACT_LR) cardiovascular risk factors or/and sedentary (SED) subjects, aged 20-70 years. Systolic arterial pressure was recorded at rest and simultaneously with automatic sphygmomanometers at the arms and ankles. ABI was calculated as the ratio of the lowest, highest or mean ankle pressure to the highest arm pressure.

RESULTS

Proportion of ABI_min<0.90 was 10.3% in SED_HR subjects versus 0.5% and 1.2%, respectively, in ACT_HR and ACT_LR groups. The averaged ABI value of each group was in the normal range in all groups (ABI>0.90) but was significantly lower in SED_HR compared with all active participants (p<0.001). Regression lines from ABI_mean versus age could lead to approximately +0.05 every 15 years of age in apparently healthy active participants (ACT_LR).

CONCLUSION

ABI at rest increases with the increase in age in the groups of low-risk asymptomatic middle-aged trained adults. The previously reported decrease in ABI with age is found only in SED_HR subjects, and is very likely to rely on the increased prevalence of asymptomatic arterial disease in this group. The increase of ABI with age is consistent with the 'physiological' stiffness observed in ageing arteries even in the absence of 'pathological' atherosclerotic lesions.

TRIAL REGISTRATION NUMBER

NIH clinicaltrial.gov: NCT01812343.

Dynamic characteristics of T2*-weighted signal in calf muscles of peripheral artery disease during low-intensity exercise

PURPOSE

To evaluate the dynamic characteristics of T2* -weighted signal change in exercising skeletal muscle of healthy subjects and peripheral artery disease (PAD) patients under a low-intensity exercise paradigm.

MATERIALS AND METHODS

Nine PAD patients and nine age- and sex-matched healthy volunteers underwent a low-intensity exercise paradigm while magnetic resonance imaging (MRI) (3.0T) was obtained. T2*-weighted signal time-courses in lateral gastrocnemius, medial gastrocnemius, soleus, and tibialis anterior were acquired and analyzed. Correlations were performed between dynamic T2*-weighted signal and changes in heart rate, mean arterial pressure, leg pain, and perceived exertion.

RESULTS

A significant signal decrease was observed during exercise in soleus and tibialis anterior of healthy participants (P = 0.0007-0.04 and 0.001-0.009, respectively). In PAD, negative signals were observed (P = 0.008-0.02 and 0.003-0.01, respectively) in soleus and lateral gastrocnemius during the early exercise stage. Then the signal gradually increased above the baseline in the lateral gastrocnemius during and after exercise in six of the eight patients who completed the study. This signal increase in patients' lateral gastrocnemius was significantly greater than in healthy subjects' during the later exercise stage (two-sample t-tests, P = 0.001-0.03). Heart rate and mean arterial pressure responses to exercise were significantly higher in PAD than healthy subjects (P = 0.036 and 0.008, respectively) and the patients experienced greater leg pain and exertion (P = 0.006 and P = 0.0014, respectively).

CONCLUSION

During low-intensity exercise, there were different dynamic T2*-weighted signal behavior in the healthy and PAD exercising muscles.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:40-48.

Flow Mediated Dilatation, Carotid Intima Media Thickness, Ankle Brachial Pressure Index and Pulse Pressure in Young Male Post Myocardial Infarction Patients in India

INTRODUCTION

Due to increase in Coronary Artery Disease (CAD) at a younger age, we should try to diagnose atherosclerotic process and population at risk, at the earliest. Flow Mediated Dilatation (FMD), Carotid Intima-Media Thickness (CIMT) and Ankle-Brachial Pressure Index (ABI) are probable markers for early atherosclerosis and may be useful in coronary risk stratification.

AIM

To compare and correlate the FMD, CIMT, ABI and Pulse Pressure (PP) in young male patients of Myocardial Infarction (MI) with age and sex matched healthy controls.

MATERIALS AND METHODS

Eighty male patients of MI aged ≤45 years, who presented to the Cardiac Care Unit and Department of Medicine of Guru Teg Bahadur Hospital, Delhi, India, from November 2010 to April 2012 were recruited consecutively for this case control study and same number of age and sex matched healthy controls were also analyzed. Six weeks after MI, FMD of the brachial artery, intima media thickness of carotid artery, ABPI and PP were measured in the cases and compared with healthy controls.

RESULTS

The FMD was lower among young patients of MI than controls (p<0.001). CIMT was higher among cases than controls (p=0.001). ABI was lower among cases than controls (p<0.001). Compared to controls, PP was higher among cases (p=0.001). In all subjects, a negative correlation between FMD and CIMT (r=-0.220, p=0.005) and a positive correlation between FMD and ABPI (r=0.304, p<0.001) was found. A statistically significant negative correlation was found between endothelial dependent FMD and PP among cases and control groups (r=-0.209, p=0.007).

CONCLUSION

Biophysical parameters were deranged in young post MI patients. Majority of our young male patients fell in low risk Framingham risk score but still they manifested with CAD. Despite six weeks of treatment among young male patients of MI, various biophysical parameters were still deranged.

Classifying patients with lumbar spinal stenosis using painDETECT: a cross-sectional study

BACKGROUND

The pathological mechanisms of lumbar spinal stenosis are unclear. Family doctors in the primary care setting may perform medical examinations of patients with lumbar spinal stenosis. Our aim was to use the painDETECT questionnaire to quantify the pathological mechanisms of low back pain and/or leg pain caused by lumbar spinal stenosis.

METHODS

We enrolled 102 patients (37 men, 65 women) who had been newly diagnosed with lumbar spinal stenosis at 2 facilities. The patients' conditions were evaluated using the painDETECT questionnaire, Numerical Rating Scale, Roland-Morris Disability Questionnaire, Japanese Orthopaedic Association Back Pain Evaluation Questionnaire, and 36-Item Short-Form Health Survey. The pathological mechanisms of low back pain and/or leg pain caused by lumbar spinal stenosis were classified based on results of the painDETECT questionnaire as nociceptive pain, neuropathic pain, or unclear type of pain (mixed pain). Statistical analyses were performed using the Kruskal-Wallis test. A value of p < 0.05 was considered to indicate statistical significance.

RESULTS

The mean age of all patients in this study was 70.3 ± 2 years. The male:female distribution was 37:65 (36.3:63.7 %). In all, 72 (70.6 %) patients had chronic pain (duration of ≥3 months), and 30 (29.4 %) had subacute or acute pain (duration of <3 months). The pain was classified as nociceptive in 59 patients (57.9 %), neuropathic in 18 (17.6 %), and unclear in 25 (24.5 %). The neuropathic pain group had a significantly lower quality of life (p < 0.05) than did the other groups.

CONCLUSIONS

Patients with neuropathic back and/or leg pain caused by lumbar spinal stenosis may have lower physical and/or psychological quality of life than patients with such pain caused by other mechanisms.

Clinical characteristics of foot ulceration in people with chronic gout

Gout is the most common form of inflammatory arthritis and it has an affliction to the foot. Foot involvement in gout has been linked to foot pain, impairment and disability. There has been limited research on the effect of ulceration on foot pain, impairment, disability and health-related quality of life in patients already living with gout. The aim of the study was to describe the wound characteristics and the effect on foot pain, disability and health-related quality of life in patients with foot ulceration associated with gout. Participants were recruited from rheumatology clinics in Auckland, New Zealand. All the current foot ulceration sites and wound characteristics were recorded using the TIME wound assessment tool. The outcome measures included general pain, patient global assessment scale, foot pain, disability and impairment. Participants completed the Cardiff Wound Impact Schedule to assess the effect of ulcers on health-related quality of life. Sensory loss, vibrational thresholds and ankle brachial pressure index were collated to assess for lower limb arterial disease. Six participants were predominantly older men with a long duration of gout, high rates of obesity and co-morbidities such as hypertension, hyperlipidaemia, diabetes and cardiovascular disease. The mean (SD) duration of the foot ulcers was 4 (2) months. The majority of foot ulcers observed were 0·5 cm(2) or smaller superficial thickness with surrounding callus. Partial thickness and full-thickness ulcers were also observed. Two patients presented with ulcers on multiple sites. There was only one case of infection. Gouty tophi were evident in most of the wounds. The dorsal aspect of the third toe was found to ulcerate in most cases. Moderate scores of foot pain, disability, impairment and health-related quality of life were observed. Most participants wore shoes deemed as poor. Foot ulceration in gout is chronic and multiple ulcers can occur with the potential of leading to delayed wound healing, infection and a reduced quality of life. Poor footwear may contribute to the development and delayed healing of ulceration in people with gout.

The Use of Best Practice in the Treatment of a Complex Diabetic Foot Ulcer: A Case Report

BACKGROUND AND PURPOSE

Published guidelines for effective management of diabetic foot ulcers (DFU) include total contact casting (TCC). The purpose of this case study is to describe the application of best practice guidelines for the treatment of a diabetic foot ulcer (DFU) in a complex patient where TCC offloading could not be utilized.

CASE DESCRIPTION

The patient was a 47 year-old female with a five-plus year history of a full-thickness DFU on the left plantar mid-foot. Treatment included sharp and ultrasound debridement, the use of a silver hydrofiber dressing, edema management via compression therapy, negative pressure wound therapy, offloading via customized 1/4 inch adhesive-backed felt applied to the plantar foot in addition to an offloading boot and use of a wheelchair, patient education regarding diabetes management, and the application of a bilayered living skin-equivalent biologic dressing.

OUTCOMES

At 15 weeks the wound was closed and the patient was transitioned into diabetic footwear.

DISCUSSION

The felt offloading was a beneficial alternative to TCC. The patient's longer than average healing rate may have been complicated by the duration of her wound, her 41 year history of diabetes, and the fact that gold standard offloading (TCC) was not able to be used. Further research is needed regarding the use of felt for offloading, such as application technique for wounds on different areas of the foot, comparison of different types of felt, and the use of felt in conjunction with various offloading devices.

Factors Affecting Penetration of Ciprofloxacin in Lower Extremity Ischemic Tissues

The aims of this study were to evaluate factors influencing the distribution of ciprofloxacin in tissue of patients suffering from varying degrees of peripheral arterial disease (PAD). Blood and tissue samples were collected from patients undergoing debridement or amputation procedures and the amount of ciprofloxacin in them was determined using high-performance liquid chromatography. All patients were administered a 200-mg dose of intravenous ciprofloxacin prior to the debridement or amputation procedure. Data, including patient gender, age, type of diabetes, presence of neuropathy, medications taken, and severity of PAD were collected. These data were then analyzed to determine factors influencing the concentrations of ciprofloxacin in tissue of the lower limbs. The Kruskal-Wallis test, Spearman correlation, and chi-square test were used to relate covariates and fixed factors with the concentration of ciprofloxacin in tissue. Following bivariate analysis, a 3-predictor regression model was fitted to predict tissue concentrations of ciprofloxacin given information about these predictors. Blood and tissue samples were collected from 50 patients having an average age of 68 years. Thirty-three patients were males and 35 patients suffered from type 2 diabetes. The average number of medications that these patients were taking was 10. The majority of patients (n = 35) were suffering from severe PAD. Tissue concentrations of ciprofloxacin were mainly related to plasma concentrations of ciprofloxacin, number of medications that the patients were taking and severity of PAD.

Validation of a Brazilian Portuguese Version of the Walking Estimated-Limitation Calculated by History (WELCH)

Background

The Walking Estimated-Limitation Calculated by History (WELCH) questionnaire has been proposed to evaluate walking impairment in patients with intermittent claudication (IC), presenting satisfactory psychometric properties. However, a Brazilian Portuguese version of the questionnaire is unavailable, limiting its application in Brazilian patients.

Objective

To analyze the psychometric properties of a translated Brazilian Portuguese version of the WELCH in Brazilian patients with IC.

Methods

Eighty-four patients with IC participated in the study. After translation and back-translation, carried out by two independent translators, the concurrent validity of the WELCH was analyzed by correlating the questionnaire scores with the walking capacity assessed with the Gardner treadmill test. To determine the reliability of the WELCH, internal consistency and test-retest reliability with a seven-day interval between the two questionnaire applications were calculated.

Results

There were significant correlations between the WELCH score and the claudication onset distance (r = 0.64, p = 0.01) and total walking distance (r = 0.61, p = 0.01). The internal consistency was 0.84 and the intraclass correlation coefficient between questionnaire evaluations was 0.84. There were no differences in WELCH scores between the two questionnaire applications.

Conclusion

The Brazilian Portuguese version of the WELCH presents adequate validity and reliability indicators, which support its application to Brazilian patients with IC.

Lower limb biomechanical characteristics of patients with neuropathic diabetic foot ulcers: the diabetes foot ulcer study protocol

BACKGROUND

Foot ulceration is the main precursor to lower limb amputation in patients with type 2 diabetes worldwide. Biomechanical factors have been implicated in the development of foot ulceration; however the association of these factors to ulcer healing remains less clear. It may be hypothesised that abnormalities in temporal spatial parameters (stride to stride measurements), kinematics (joint movements), kinetics (forces on the lower limb) and plantar pressures (pressure placed on the foot during walking) contribute to foot ulcer healing. The primary aim of this study is to establish the biomechanical characteristics (temporal spatial parameters, kinematics, kinetics and plantar pressures) of patients with plantar neuropathic foot ulcers compared to controls without a history of foot ulcers. The secondary aim is to assess the same biomechanical characteristics in patients with foot ulcers and controls over-time to assess whether these characteristics remain the same or change throughout ulcer healing.

METHODS/DESIGN

The design is a case-control study nested in a six-month longitudinal study. Cases will be participants with active plantar neuropathic foot ulcers (DFU group). Controls will consist of patients with type 2 diabetes (DMC group) and healthy participants (HC group) with no history of foot ulceration. Standardised gait and plantar pressure protocols will be used to collect biomechanical data at baseline, three and six months. Descriptive variables and primary and secondary outcome variables will be compared between the three groups at baseline and follow-up.

DISCUSSION

It is anticipated that the findings from this longitudinal study will provide important information regarding the biomechanical characteristic of type 2 diabetes patients with neuropathic foot ulcers. We hypothesise that people with foot ulcers will demonstrate a significantly compromised gait pattern (reduced temporal spatial parameters, kinematics and kinetics) at base line and then throughout the follow-up period compared to controls. The study may provide evidence for the design of gait-retraining, neuro-muscular conditioning and other approaches to off-load the limbs of those with foot ulcers in order to reduce the mechanical loading on the foot during gait and promote ulcer healing.

Screening for peripheral neuropathy and peripheral arterial disease in persons with diabetes mellitus in a Nigerian University Teaching Hospital

BACKGROUND

Identifying the risk factors for diabetes mellitus related foot ulceration would save more limbs from amputation. This report focuses on the determining the burden of peripheral arterial disease and neuropathy in persons with diabetes mellitus (DM).

METHODS

This is a descriptive study carried out in the Diabetic Clinic of the Lagos State University Teaching Hospital in patients with DM who had no past/present history of foot ulceration. Biothesiometry was employed and ankle brachial pressure indices were measured to evaluate for neuropathy and peripheral arterial disease (PAD) respectively.

RESULTS

A total of 225 persons living with DM who met inclusion criteria were recruited consecutively over a 3 months period. Age range was 28-87 years with the mean [61.4 (10.8)] and median (63) years respectively. Patients symptomatic for neuropathy and PAD were 37 and 40 % respectively of the study population. An older age of >60 years and poor glycaemic control were potential predictors of neuropathy. Neuropathy and PAD occurred commonly in the seventh decade of life.

CONCLUSION

Given the fairly high proportions of neuropathy and PAD in our patients with DM, we recommend that they be routinely examined in persons with DM.

Atypical leg symptoms: does routine measurement of the ankle brachial pressure index (ABPI) in primary care benefit patients?

Background : Managing patients with atypical leg symptoms in primary care can be problematic. Determining the ankle brachial pressure index (ABPI) may be readily performed to help diagnose peripheral arterial disease, but is often omitted where signs and symptoms are unclear. Question: Does routine measurement of ABPI in patients with atypical leg symptoms aid management increase satisfaction and safely reduce hospital referral? Methodology: Patients with atypical leg symptoms but no skin changes or neurological symptoms underwent clinical review and Doppler ABPI measurement (suspicious finding ≤ 1.0). Testing was performed by the same doctor (study period: 30 months). Patient outcomes were determined from practice records, hospital letters and a telephone survey. Results : The study comprised 35 consecutive patients (males: N = 15), mean age 64 years (range: 39-88). Presentation included pain, cold feet, cramps, irritation and concerns regarding circulation. Prior to ABPI measurement, referral was considered necessary in 10, not required in 22 and unclear in 3. ABPI changed the referral decision in 10 (29%) and confirmed the decision in 25 (71%). During the study, 10 (29%) patients were referred (9 vascular, 1 neurology). Amongst the vascular referrals, significant peripheral arterial disease has been confirmed in six patients. A further two patients are under review and one did not attend. To date, lack of referral in patients with atypical leg symptoms but a normal ABPI has not increased morbidity. Current status was assessed by telephone review in 16/35 (46% contact rate; mean 18 months, range 2-28). Fifteen patients (94%) appreciated that their symptoms had been quickly and conveniently assessed, 8/11 (73%) with a normal ABPI were reassured by their result and in 8/11 symptoms have resolved. Discussion/Conclusion: APBI conveniently aids management of atypical leg symptoms by detecting unexpected peripheral arterial disease, avoids /confirms the need for referral, reassures patients and guides reassessment. This study suggests ABPI should be used more widely.

Venous claudication in Behçet's disease

OBJECTIVE

We have previously shown that venous claudication is significantly more common among patients with Behçet's disease (BD) and had proposed that this was a "venous claudication" because it was specifically more common among men with lower extremity venous thrombosis (LEVT). With this study, we reassessed the presence of claudication prospectively by a questionnaire and a treadmill exercise.

METHODS

We studied all men: 61 BD patients with LEVT, 40 BD patients without vascular involvement, and 56 healthy controls. Venous claudication was assessed by a standardized questionnaire. In addition, patients were asked to walk on a treadmill for 10 minutes. Patients who experienced symptoms consistent with venous claudication but still able to walk and those who had to give up the treadmill exercise were noted. Ankle-brachial pressure indices measured before and after the treadmill test did not indicate any peripheral arterial disease.

RESULTS

Twenty-one BD patients with LEVT (34%), two BD patients without vascular involvement (5%), and none of the healthy controls described venous claudication when assessed with the questionnaire (P < .001). There were significantly more patients who described claudication during the treadmill exercise among patients with LEVT (21%) compared with those with no vascular disease (8%) and healthy controls (2%) (P = .002). Finally, only those with LEVT (6 of 61) had to stop the treadmill challenge because of claudication.

CONCLUSIONS

Venous claudication is a severe and frequent symptom, being present in up to one third of BD patients with LEVT. It impairs walking capacity in 10% of these patients.

High Ankle-Brachial Index Indicates Cardiovascular and Peripheral Arterial Disease in Patients With Type 2 Diabetes

We assessed the association between high ankle-brachial index (ABI) and cardiovascular disease (CVD) and peripheral arterial disease (PAD) in Chinese patients with type 2 diabetes mellitus (T2DM). The ABI was measured, and foot inspection was performed in 2080 outpatients with T2DM. The clinical characters in different ABI levels were analyzed, and the diagnostic value of high ABI to CVD and PAD was determined. Compared with the normal ABI group, the high ABI (>1.3) group had a higher prevalence of CVD and PAD but less than the low ABI (≤0.9) group. High ABI was an independent risk factor for the development of CVD and PAD. Receiver-operating characteristic curve analysis showed that the optimal cutoff of high ABI to predict CVD and PAD was 1.43 and 1.45, respectively. The odds ratio of high ABI for CVD and PAD was 2.25 and 6.97, respectively, after adjusting for other confounding risk factors. In conclusion, high ABI indicated the risk of CVD and PAD in Chinese populations with T2DM.

Mechanical, biological and structural characterization of human atherosclerotic femoral plaque tissue

The failure of endovascular treatments of peripheral arterial disease represents a critical clinical issue. Specialized data are required to tailor such procedures to account for the mechanical response of the diseased femoral arterial tissue to medical device deployment. The purpose of this study is to characterize the mechanical response of atherosclerotic femoral arterial tissue to large deformation, the conditions typical of angioplasty and stenting, and also to determine the mechanically induced failure properties and to relate this behaviour to biological content and structural composition using uniaxial testing, Fourier transform infrared spectroscopy and scanning electron microscopy. Mechanical and biological characterization of 20 plaque samples obtained from femoral endarterectomy identified three distinct classifications. "Lightly calcified" samples display linear mechanical responses and fail at relatively high stretch. "Moderately calcified" samples undergo an increase in stiffness and ultimate strength coupled with a decrease in ductility. Structural characterization reveals calcified nodules within this group that may be acting to reinforce the tissue matrix, thus increasing the stiffness and ultimate strength. "Heavily calcified" samples account for the majority of samples tested and exhibit significantly reduced ultimate strength and ductility compared to the preceding groups. Structural characterization of this group reveals large areas of calcified tissue dominating the failure cross-sections of the samples. The frequency and structural dominance of these features solely within this group offers an explanation as to the reduced ultimate strength and ductility and highlights the need for modern peripheral endovascular devices to account for this behaviour during novel medical device design.

Study of the association of adrenomedullin and basic-fibroblast growth factors with the peripheral arterial blood flow and endothelial dysfunction biomarkers in type 2 diabetic patients with peripheral vascular insufficiency

Background

Progressive micro-vascular vaso-degeneration is the major factor in progression of diabetic complications. Adrenomedullin (AM) and basic-Fibroblast growth factor (b-FGF) are strongly correlated with angiogenesis in vascular diseases. This study aims to provide base line data regarding the vascular effects and correlation of AM, and b-FGF with the peripheral blood flow in diabetic patients with peripheral vascular disease (PVD), and their effect on endothelial dysfunction markers. Ninety age- and sex matched females were enrolled in the study: 30 were controls, 30 had diabetes without complications (group II) and 30 had diabetes with PVD (group III) diagnosed by ankle/ brachial index (A/BI). Plasma levels of AM, b-FGF, intercellular adhesion molecule −1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were measured by indirect enzyme immunoassay (ELISA).

Results

There was a significant increase in plasma AM, VCAM-1and ICAM-1, while a significant decrease in plasma b-FGF in diabetic patients with PVD (p < 0.05). A positive correlation was observed between plasma AM, b-FGF and A/BI and a negative correlation with VCAM −1 and ICAM in diabetic PVD. AM was not a predictor, while b-FG, VCAM-1 and ICAM-1 could be predictors for peripheral blood flow in diabetic PVD.

Conclusion

This study elucidates for the first time that AM and b-FGF are correlated and have a direct impact on the peripheral blood flow, the rise of AM in diabetic PVD may be a consecutive and compensatory vasculo-protective effect as its angiogenic and anti-inflammatory properties act to relief the endothelial insult. Down expression of b-FGF may be a predisposing factor for micro-vascular derangement. It is not clear if the rise of AM and the decline of b- FGF levels may be consequences or predisposing factors for VCAM-1 and ICAM-1 elevation as these endothelial dysfunction biomarkers could reduce peripheral blood flow and vascular integrity. It is optimistic to believe that drug intervention through AM and b-FGF administration together with reversing the endothelial inflammatory process by targeting VCAM and ICAM could reduce the prevalence of diabetic vascular complications, reduce the risk of cerebrovascular and cardiovascular morbidity in diabetes through normalizing vascular endothelium function and peripheral blood flow.

The relationship between childhood BMI and adult serum cholesterol, LDL, and ankle brachial index

OBJECTIVE

Effects of childhood overweight may persist into adulthood. We assessed the effect of childhood overweight on cardiovascular disease high risk factor levels in the same participants as adults, after controlling for adult body mass index (BMI) status.

DESIGN

A subset of participants in an observational study (Heartwatch) were contacted approximately 26-27 years after initial enrollment to participate in a follow-up study on the long-term effects of childhood overweight. During follow-up, BMI, waist:hip circumference (WHC), blood pressure (BP), serum lipids, and ankle brachial index (ABI) were measured; additional BMI measures throughout childhood were obtained as available from the electronic medical record. Primary outcomes were ABI and serum low density lipoprotein (LDL).

SETTING

The 1982 Heartwatch study was conducted with children participants living in Marshfield, Wisconsin; follow-up included original participants who were re-contacted and agreed to be enrolled.

PARTICIPANTS

Participants were a stratified random sample of eligible participants in the original 1982 Heartwatch study. Of the original 3106 participants, 647 adult participants completed follow-up exams.

RESULTS

Among males with 1982 BMI ≥ 85(th) percentile, adult BMI, WHC, (both P ≤ 0.001), ABI (P = 0.001), total cholesterol (P = 0.01), LDL (P = 0.003) and BP (P < 0.02) were higher in 2008-2009 as compared to males with 1982 BMI < 85(th) percentile. Among females, BMI, BP and WHC (all P < 0.001) were higher in 2008-2009. BMI in 1982 and 2008-2009 were correlated [r = 0.56 (males); 0.58 (females), P < 0.001]. 2008-2009 BMI was more strongly correlated with 2008-2009 measures of ABI (r = 0.16, P = 0.006, males) and high LDL [r = 0.18, P = 0.002 (males); r = 0.11, P = 0.046 (females)]. 1982 BMI was not independently associated with ABI or LDL after adjusting for adult BMI.

CONCLUSION

In a cohort studying childhood and adult overweight, childhood BMI was associated with health outcomes relating to cardiovascular disease in adulthood. However, childhood BMI was not independently related to LDL-C or ABI levels in adulthood after accounting for adult BMI. Longitudinal measurements of BMI and other health risk factors were not found to improve accuracy of models for high cardiovascular disease risk factor levels.

Evaluation of peripheral arterial disease in prediabetes

BACKGROUND

The prevalence of prediabetes in the world continues to increase. These patients have elevated the risk of atherosclerosis. The current study was designed to assess the prevalence of peripheral arterial disease (PAD) and its related risk factors in prediabetes patients.

METHODS

This was the case-control study in which 135 adults in three groups: Diabetes, prediabetes, and normal were studied. We evaluated the prevalence of PAD through the measurement of ankle-brachial index (ABI). All the patients were interviewed about demographic and medical data, including age, sex, disease duration, body mass index, hypertension (HTN), fasting blood glucose, hemoglobin A1C (HbA1C), lipid profile, and medication use.

RESULTS

The prevalence of PAD in diabetes patients was higher than the normal group (8.5%vs. 0.0%) (P < 0.05), but the differences between prediabetes compared with diabetes and normal group were not significant. The mean level of ABI in normal, prediabetes, and diabetes group was (1.11 ± 0.11), (1.09 ± 0.12), and (1.05 ± 0.03) respectively (P < 0.1). There were marginally significant differences of ABI observed between the normal group and the diabetes group. The observed differences between groups in the ABI were significant after adjusting the effects of age and sex (P < 0.05). There was an association observed between ABI and HbA1C in diabetes patients (r = 0.249, P < 0.01) and a significant association seen between PAD and HTN in the prediabetes group (P < 0.01).

CONCLUSIONS

Peripheral arterial disease is common in asymptomatic diabetes and prediabetes patients. Management of hypertensive prediabetes patients and early detection of PAD in this group as well as in asymptomatic patients is important.

Effect of ischemic and pharmacological preconditioning of lower limb muscle tissue on tissue oxygenation measured by near-infrared spectroscopy--a pilot study

Background

Ischemic or volatile anesthetic preconditioning is defined as tissue protection from impending ischemic cell damage by repetitive short periods of tissue exposure to ischemia or volatile anesthetics. Objective of this study was to elucidate, if ischemic preconditioning and pharmacological preconditioning with sevoflurane have effects on muscle tissue oxygen saturation in patients undergoing surgical revascularization of the lower limb.

Methods

In this prospective randomized pilot study ischemic and pharmacological (sevoflurane) preconditioning was performed in 40 patients with lower limb arterial occlusive disease undergoing surgical revascularization. Sevoflurane preconditioning was performed in one group (N = 20) by repetitive application of sevoflurane for six minutes interspersed by six minutes of washout. Thereafter, ischemic preconditioning was performed in all patients (N = 40) by repetitive clamping of the femoral artery for six minutes interspersed by six minutes of reperfusion. The effect of both procedures on leg muscle tissue oxygen saturation (rSO₂) was measured by near-infrared spectroscopy during both procedures and during surgery and reperfusion (INVOS® 5100C Oxymeter with Small Adult SomaSensor® SAFB-SM, Somanetics, Troy, Michigan, USA).

Results

Repetitive clamping and reperfusion of the femoral artery resulted in significant cyclic decrease and increase of muscle rSO₂ (p < 0.0001). Pharmacological preconditioning with sevoflurane resulted in a faster and higher increase of rSO₂ during postoperative reperfusion (Maximal 111% baseline ± 20 versus 103% baseline ± 14, p = 0.008) consistent with an additional effect of pharmacological preconditioning on leg perfusion.

Conclusions

Ischemic preconditioning of lower limb muscle tissue and pharmacological preconditioning with sevoflurane have an effect on tissue oxygenation in patients with lower limb occlusive arterial disease.

Trial registration

The trial has been registrated at http://www.ClinicalTrial.gov, Trial Number: NCT02038062 at 14 January 2014.

Kinematic mapping reveals different spatial distributions of center of pressure high-speed regions under somatosensory loss

The spatial distribution of center-of-pressure speed during postural tasks and its changes due to somatosensory constraint (temporary ischemic hypoxia on ankle/feet) were investigated in young, healthy subjects (n = 13). A single high-speed region in the central region of the statokinesigram was observed during postural tasks with full sensory information. A significant increase in the quantity of high-speed regions was observed during ischemia and somatosensory constraint, whereas a significant increase in the quantity of high-speed regions localized more distant to the center of center-of-pressure area occurred under somatosensory constraints, suggesting a redirection of center-of-pressure trajectory to adjust the position of the center of mass with respect to the egocentric reference of balance.

The effects of sulodexide on both clinical and molecular parameters in patients with mixed arterial and venous ulcers of lower limbs

BACKGROUND

Mixed venous and arterial ulcers account for approximately 15%-30% of all venous leg ulcerations. Several studies have shown that matrix metalloproteinases (MMPs) and neutrophil gelatinase-associated lipocalin (NGAL) play a central role in the pathophysiology of venous and arterial diseases. Some studies have shown the efficacy of glycosaminoglycans, such as sulodexide (SDX), in treating patients with leg ulcers. The aim of this study was to evaluate clinical effects of SDX and its correlation with MMPs and NGAL expression in patients with mixed arterial and venous leg ulcers.

METHODS

Patients eligible for this study were of both sexes, older than 20 years, and with a clinical and instrumental diagnosis of mixed ulcer.

RESULTS

Fifty-three patients of both sexes were enrolled and divided into two groups by means of randomization tables. Group A (treated group) comprised 18 females and ten males (median age: 68.7 years) treated with standard treatment (compression therapy and surgery) + SDX (600 lipoprotein lipase-releasing units/day intramuscularly) for 15 days followed by SDX 250 lipase-releasing units every 12 hours day orally for 6 months as adjunctive treatment. Group B (control group) comprised 17 females and eight males (median age: 64.2 years) treated with standard treatment only (compression therapy and surgery). The type of surgery was chosen according to anatomical level of vein incompetence: superficial venous open surgery and/or subfascial endoscopic perforating surgery. In all enrolled patients, blood samples were collected in order to evaluate the plasma levels of MMPs and NGAL through enzyme-linked immunosorbent assay. These results were compared to another control group (Group C) of healthy individuals. Moreover, biopsies of ulcers were taken to evaluate the tissue expression of MMPs and NGAL through Western blot analysis. Our results revealed that SDX treatment is able to reduce both plasma levels and tissue expression of MMPs improving the clinical conditions in patients with mixed ulcers.

CONCLUSION

Inhibition of MMPs could represent a possible therapeutic intervention to limit the progression of leg ulceration. In particular, our findings demonstrate the efficacy of SDX in patients with mixed arterial and venous chronic ulcers of the lower limbs.

Current utility of the ankle-brachial index (ABI) in general practice: implications for its use in cardiovascular disease screening

Background

Peripheral arterial disease (PAD) is a marker of systemic atherosclerosis and associated with a three to six fold increased risk of death from cardiovascular causes. Furthermore, it is typically asymptomatic and under-diagnosed; this has resulted in escalating calls for the instigation of Primary Care PAD screening via Ankle Brachial Index (ABI) measurement. However, there is limited evidence regarding the feasibility of this and if the requisite core skills and knowledge for such a task already exist within primary care. This study aimed to determine the current utility of ABI measurement in general practices across Wales, with consideration of the implications for its use as a cardiovascular risk screening tool.

Method

A self-reporting questionnaire was distributed to all 478 General Practices within Wales, sent via their responsible Health Boards.

Results

The survey response rate was 20%. ABI measurement is primarily performed by nurses (93%) for the purpose of wound management (90%). It is infrequently (73% < 4 times per month) and often incorrectly used (42% out of compliance with current ABI guidance). Only 52% of general practitioners and 16% of nurses reported that patients with an ABI of ≤ 0.9 require aggressive cardiovascular disease risk factor modification (as recommended by current national and international guidelines).

Conclusion

ABI measurement is an under-utilised and often incorrectly performed procedure in the surveyed general practices. Prior to its potential adoption as a formalised screening tool for cardiovascular disease, there is a need for a robust training programme with standardised methodology in order to optimise accuracy and consistency of results. The significance of a diagnosis of PAD, in terms of associated increased cardiovascular risk and the necessary risk factor modification, needs to be highlighted.

[Renaissance of pedicled flaps in oral and maxillofacial surgery]

A retrospective analysis in the period 2007 to 2011 included 71 surgically treated patients for carcinoma of the head and neck region and subsequent reconstruction with 36 pedicled distant flaps and 47 free flaps. Patient specific parameters of data collection with SPSS 17.0 were age and sex distribution, TNM stage and treatment. The specific type of flap reconstruction, duration of surgery, complications, intensive care and inpatient treatment were recorded. The results showed that the healing process was uneventful in 26 (72.2 %) pedicled flaps, 14 (38.9 %) pedicled flaps were transplanted in a preoperatively irradiated area of the head and neck region and in 86.0 % with a positive healing process. Tumor stage, general physical condition of the patient and type of therapy are the key parameters for the choice of reconstruction.

Endovascular treatment for intermittent claudication in patients with peripheral arterial disease: a systematic review

BACKGROUND

We performed a systematic review and meta-analysis to examine whether patients with intermittent claudication can benefit from endovascular treatment (EVT).

METHODS

A prespecified search strategy was used to identify relevant studies in the MEDLINE, Embase, and Cochrane databases. A total of 10 different randomized, controlled trials were reviewed. Random effects meta-analysis was performed between the EVT plus conservative treatment (CT) group and the CT group alone. Also, random effects meta-analysis was performed between the EVT group and the supervised exercise therapy (SET) group.

RESULTS

The independent effect of EVT could directly improve the ankle-brachial index (ABI) and walking performance over the short term, but not over the long term. Moreover, compared to SET, EVT had the superiority in improving the ABI, while SET could improve walking performance more efficiently.

CONCLUSIONS

Patients with intermittent claudication may benefit from endovascular treatment over the short term (within 12 months), with improvements in ABI, intermittent claudication distance, and maximum walking distance. However, considering improvements on walking performance (especially over the long term), SET is recommended.